Auxiliary hydraulic device for presses



May 21, 1940. H. F. MacMILLIN 2,201,443

AUXILIARY HYDRAULIC DEVICE FOR PRESSES Original Filed Aug. 16, 1934 2 Sheets-Sheet 1 v I I l I I IN VENTOR I Ham/P0 Moe/W //Y BY A TTORNEYS May 21, 1940- RF. MacMILLIN AUX ILIARY HYDRAULIC I JEVICE FOR PRESSES 2 Sheets-Sheet 2 Original Filed Aug. 16, 1934 l A E S :5 S m? IN VEN TOR /70M4/?D E MM/V/LL/IY A TTORNEYS I Patented May21, 1940 UNITEDSTA'tE s PATENT OFFICE hummer- YDRAULIC DEVICE Fort masses.

- Howard .MacMi llin,

signor Mount .Gilead, Ohio, as-

tofThe Hydraulic Press Corporation,

Inc., -Wilmington,-Del., a corporation of Delaware Original application August16, 1934, Serial No. 740,148, now Patent No. 2,128,152, dated August 23, 1938. Divided and this application August 24, 1936, Serial No. 97,578

Claims.

erated being available for operating various -hy'- draulically-actuated devices and/or providing pressure control.

1 Another object is'to provide a platen-operated hydraulic generating'arrangement of the above mentioned type, the auxiliary hydraulic ram be-- ing of a double-acting. nature. these generator rams being connected to an external hydraulic circuit so that the volume given the auxiliary hydraulic'ram by the generator rams is amplified by the efiect of this external circuit.

Another object is to provide a press-having its platen moved byv whatever means, with an auxiliary hydraulic pressing 'ram connected to an external hydraulic actuating circuit.

This application is. a division of my copending application, Ser. No..740,148,'filed August 16,1934,

now matured into-Patent No. 2,128,152, dated August 23, 1938.

In the drawings:

Figure 1 is a front elevation, partly in section, of a press having hydraulic generator rams and an auxiliary hydraulic ram with an external hydraulic circuit and connections whereby the action of the rams is amplified.

Figure 2 is a diagrammatic view of a circuit similar to Figure -1, but employing a cam-actuated reversing valvewith .a variable delivery hydraulic pump.

- Figure 3 is a diagrammatic. view similar to Figure 2, but employing a cam-actuated reversing valve with a constant delivery hydraulic pump;

Press with single-acting-generator rams 5 platen 8 for longitudinal reciprocation. The

keeping of the platen 8 in engagement with the guide portion 1 is assisted by the retaining plates 9, bolted to the side members 2 of the press.

The press platen 8 may be moved in any convenient manner, such as mechanically or hydrauto provide a press lically. For purposes of illustration, a geardriven mechanical crank press is shown, but other types may be used without departing from ,shown, the platen 8 is provided with a cross shaft l8, journaled in bearings H on the upper portion of theplaten 8. Pivotally engaging the cross shaft lllof the platen 8 is a connecting rod l2 having a lower bearing l3, surrounding the cross shaft l8. At its upper end, the connecting rod I2 is provided with an upper bearing I4 which surrounds the crank portion l5 of the main drive shaft 16. The latter is journaled in bearings II, mounted upon the side members 2 of the press.

The driving end of the main driveshaft I8 is the scope of my invention. In the form of press provided with a gear l8 for this purpose. The

v gear I8 is connected by a clutch mechanism within the clutch housing IS in such a manner that the gear l8 may be connected or disconnected from the main drive shaft I8, as desired. The clutch mechanismwithin the clutch housing I8 is actuated by the crank arm 28 mounted on the clutch shaft 2|, and connected by the link 22 to the pedal rod 23. The latter is reciprocably supported in the bosses 24 attached to one of the side members 2, and is secured at its lower end by the pivotal connection 25 to the foot pedal 28. By depressing or releasing the foot pedal 28, the gear l8 may be made to operatively engage the main drive shaft H5 or rotate loosely upon it. In this manner the foot pedal 28 controls the press to provide for its executing working strokes or for its remaining idle, as may be desired.

The gear I8 is driven by a pinion 21, meshing therewith, and mounted upon the countershaft 28 journaled in bearings attached to the side members 2. The opposite end of the countershaft 28 from the pinion' 2'I ,bears a flywheel 38 and a pulley 3|, whereby the press may be driven, as from an electric motor belted to this pulley. Accordingly, when the pulley 3| is thus rotated, the gear l8 also rotates loosely upon the main drive shaft 16. When the foot pedal 26 is depressed, the gear 18 drivingly engages the main shaft l6 and causes the crank portion l5 thereof to move in an orbital path. This movement causes the connecting rod l2 to move up and down, carrying with it the platen a. J

-The platen 8 in its lower portion is provided with a pair of generator cylinder bores 52 and 53 and an auxiliary pressing cylinder ,bore 54. These cylinder boresare connected to the cylinder bore 54 by the passages 55 and 56. Reciprocably mounted within the cylinder bores 52 and 53 are hydraulic generator rams 58 and 51, having their lower ends secured in sockets 35, in the base I (Figure 1). Leakage from the generator cylinders 52 and 53 is prevented by the provision of the packings 31 adapted to be compressed by glands 38. Mounted for reciprocation in the auxiliary pressing cylinder bore 54 is the double-acting auxiliary pressing ram 45, having an upper enlarged portion 48 and a lower reduced portion 49. Leakage from the cylinder bore 54 is prevented by the packing 43, engaged by the gland 44, which surrounds the reduced portion 49 of the auxiliary pressing ram 45.

It will be observed that the right-hand cylinder 53 is connected at its upper end by the passage 55 to the space above the enlarged head 48 of the auxiliary hydraulic ram 45, whereas the upper end of the cylinder 52 is connected by the oblique passage 55 to the space below the enlarged head 48. The pistons 51 and 58, however, are provided with hollow longitudinal bores 59, and; thus act like telescoping connections, and to some extent like pistons. The bores 59 are connected at their lower ends to the pipes 88 and 5|, respectively.

The pipes 58 and 8| lead to the opposite ports 52 and 63, respectively, of a hydraulic pump 64. This hydraulic pump is of the variable delivery type having a flow control rod 65, which when moved in or out, varies the quantity and direction of the pressure fluid passing through the pipes 58 and GI. The flow control rod 55 is connected by the link 86 to one arm oif the bellcrank 61, the other arm thereof being connected by the link 68 to the cam push rod69. The latter is reciprocably mounted in the bearings 18 attached to the upper frame member 3, and has a yoke II at its lower end. Mounted in the yoke II is a roller I2 which serves as a cam follower engaging the cam I3 mounted upomthe main drive shaft I5 of the press. The coil spring I4 urges the cam follower I2 downward against the cam 13 (Figure 1).

Since the spaces on the opposite'sides of the enlarged head 48 of the auxiliary pressing ram '45 are of unequal volume, a differential valve I5 is provided to supply or release fluid whenever this is necessary. This differential valve I5 is bridged across the pipes 68 and 5|, and consists of a casing 15 having end chambers 11 and 18, together with a middle chamber 19. Reciprocable in channels through the partitions through the various chambers is a valve rod 88, having enlarged heads 8I and 82 at its opposite ends. Connected to the middle chamber I9 is a pipe 83 leading downward into the tank 84, which serves as a reservoir for the working fluid. When the pipes 68 and SI become suction lines alternately, and require additional fluid, the valve member 88 shifts, allowing fluid to be drawn upward from the tank 84, through the pipe 83 and the middle chamber I9, into 'either of the end chambers II or I8, as may been adjusted so that the pump 64 will deliver such pressure fluid through the pipe 68 during the downward stroke of the platen 8. While this is occurring, the fluid in the space below the auxiliary pressing ram head 48 is forced outwardly through the oblique passage 58 into the cylinder bore 52, and passes downwardly through the bore 58 in the plunger 58, returning to the pump 84 by way of the pipe line 8|. At the same time, the fluid pressure is somewhat increased by the plunger-like effect of the fixed piston 51 in the moving cylinder 58.

when the platen 8 starts on its upward return stroke, the cam I3 causes the cam follower I2 and cam push rod 59 to descend, under the urge of the spring 14. This causes the flow control rod 55 to be drawn outwardly from the pump 54, reversing the flow of the pressure fluid delivered thereby. The pipe line 8| now becomes the pressure line, and the pressure fluid passing therethrough into the cylinder bore 52 proceeds through the oblique passage 58 into the space beneath the auxiliary pressing ram head 48 and returns to the pump 84 by way of the passage 55, the cylinder bore 58, the passage 59 and the pipe 58.

It will be understood that in place of the hydraulic pump 84, having a flow control rod 65, a non-reversible hydraulic pump may be used in connection with a reversing valve. In this arrangement (Figure 2), the valve rod I84 of the reversing valve I85 is shifted by the action of the cam 13. This moves the valve heads I85 and MI, and reverses, in an obvious manner, the flow of fluid in the lines I88, I88 and III, leading from the reversing valve I85 to the press. The high pressure check valve III pre vents a backward flow of fluid, whereas the high pressure regulating valve II2 discharges the fluid from the line I88 into the discharge line II3 leading back to the tank 84. The variable delivery pump I I4 is here provided with a servocylinder II5 connected by the pilot line II to the main pump line I". This serves to shift the flow control element oi. the pump II 4 when the pressure in the lines I" and H8 rises beyond the pressure setting of the servo-cylinder H5. The latter is adjusted by the hand wheel II 8. The line II9 leads from the opposite side of the pump II4 to the tank 84. The line III leads to the forward side 01' the pressing plunger, the line I88 to the return side thereof.

The arrangement shown in Figure 3 is similar to that shown in Figure 2 and like numerals are used, except that a constant delivery pump I28 is employed in conjunction with a pressure relief valve I2I, which discharges its flow into the tank 84 by way of the discharge line I22 when the pressure exceeds the pressure setting of the valve I2I.

It will be understood that I desire to comprehend within my invention such modifications as come within the scope of the claims and the invention.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In combination in a press, a frame, a me-' chanically movable platen, means for moving said platen, a pressing cylinder and an auxiliary cylinder carried by said platen, a hydraulically-operated double-acting pressing ram reciprocable in said pressing cylinder, and movable relatively thereto a fixedly mounted auxiliary plunger with a fluid conduit therethrough extending between said frame and said auxiliary cylinder, said auxiliary cylinder being hydraulically connected to said pressing cylinder. and means for supplying fluid under pressure to said conduit additional to the pressure fluid generated by the relative motion between said auxiliary cylinder and said auxiliary plunger whereby to provide an additional pressing eiTect to said platen.

2. In combination in a press, a mechanicallymovable platen, means for moving said platen, an auxiliary cylinder carried by said platen for generating fluid pressure in response to the motion of said platen, a hydraulically-actuated double-acting ram pressing plunger movable relatively to said platen and adapted to be operated by the fluid from said platen-operated auxiliary cylinder, and a stationarily mounted auxiliary plunger with a fluid conduit therethrough within said auxiliary cylinder, and a pump connected to supply additional fluid to said conduit to amplify the pressure of fluid generated in said platenoperated auxiliary cylinder in response to the motion of said platen whereby to provide an additional pressing effect to said ram.

3. In combination in a press, a mechanically movable platen, means for moving said platen, a pair of auxiliary pressure-generating cylinders carried by said platen and operated by the motion of said platen, a fixedly mounted tubular plunger in each auxiliary cylinder, a pressing cylinder and a double-acting piston associated with said platen and adapted to be operated in opposite directions by the pressure fluid from said pressure-generating cylinders, and a hydraulic pump connected to the tubular portions of said tubular auxiliary plungers to supply additional pressure fluid to amplify the pressure exerted upon said double-acting piston by the pressure fluid produced by said pressure-generating piston and cylinder assembly. I

4. In combination in a press, a mechanically movable platen, means for moving said platen, a pair of auxiliary pressure-generating cylinders carried by said platen and operated by the motion of said platen, a fixedly mounted tubular plunger in each auxiliary cylinder, a pressing cylinder and a double-acting piston associated with said platen and adapted to be operated in opposite directions by the pressure fluid from said pressure-generating cylinders, and a hydraulic pump connected to the tubular portions of said tubular auxiliary plungers to supply additional pressure fluid to amplify the pressure exerted upon said double-acting piston by the pressure fluid produced by said pressure-generating piston and cylinder assembly, said press having means adapted to reverse said pump when said platen reaches the limit of its working stroke.

5. In combination in a press, a mechanically movable platen, means for moving said platen, a pair of auxiliary pressure-generating cylinders carried by said platen and operated by the motion of said platen, a fixedly mounted tubular plunger in each auxiliary cylinder, a pressing cylinder and a double-acting piston associated with said platen andadapted to be operated in opposite directions by the pressure fluid from said pressure-generating cylinders, and a hydraulic pump connected to the tubular portions of said tubular auxiliary plungers to supply additional pressure fluid to amplify the pressure exerted upon said double-acting piston by the pressure fluid produced by said pressure-generating piston and cylinder assembly, said press having timing means adapted to reverse the direction of flow from said pump when said platen reaches the lower limit of its working stroke.

able delivery hydra 6. In combination in a. press, a mechanically movable platen, means for moving saidplat'en, a pair of auxiliary pressure-generating cylinders carried by said platen and operated by the motion of said platen, a fixedly mounted tubular 5 plunger in each auxiliary cylinder, a pressing cylinder and a double-acting piston associated with said platen and adapted to be operated in opposite directions by the pressure fluid from said pressure-generating cylinders, and a hydraulic pump connected to the tubular portions of said tubular auxiliary plungers to supply additional pressure fluid to amplify the pressure exerted upon said double-acting piston by the pressure fluid produced by said pressure-generating piston and cylinder assembly, said press having timing means adapted to reverse the direction of flow from said pump when said platen reaches the lower limit of its working stroke, said tim ing means being synchronized to be operated in accordance with the motion of said platen.

7. In combination in a press, a mechanically movable platen, a double-acting piston and cylinder assembly adapted to provide additional movement to the movement produced by said platen, a hydraulic pump connected to said piston and cylinder assembly to actuate the same, means responsive to the attainment of a predetermined pressure for reducing the flow from said pump to said assembly, and a pressure-generating piston and cylinder assembly operated by the motion of said platen and adapted to provide pressure fluid above said predetermined pressure.

8. In combination in a press, a'mechanically 5 reciprocable platen, a piston and cylinder assembly carried by said platen and moved in opposite directions only hydraulically, a reversible variable delivery hydraulic pump connected to said hydraulic assembly and having a flow-varying reversing member associated therewith, and mechanical means synchronized with the motion of said platen for shifting said flow-varying reversing member to reverse the flow of said pump to said hydraulic assembly when said platen reaches a predetermined position.

9. In combination in a press, a mechanically movable platen, a piston and cylinder assembly carried by said platen and moved in opposite directions only hydraulically, a reversible vari- 0 pump connected to said hydraulic assembly an having a flow-varying reversing member associated therewith, connecting. mechanism attached to said flow-varying member, and means for shifting said connecting mechanism and said flow-varying reversing member to reverse the flow of said pump when said platen reaches a predetermined position.

10. In combination in a press, a mechanically movable platen, means for moving said platen, a double-acting hydraulic piston and cylinder assembly moved in opposite directions only hydraulically associated with said platen to provide additional movement to the mechanical movement of said platen, a. constant delivery bydraulic pump connected to said hydraulic assembly, a reversing valve therebetween, means for shifting said reversing valve to reverse the flow of said pump to said hydraulic assembly when said platen reaches a. predetermined position, and 70 pressure-responsive valve means responsive to the attainment of a predetermined pressure to divert the flow of said pump from said assembly. HOWARD F. MAOMIILIN. 

